Issue #12451: Add support.create_empty_file()

We don't need to create a temporary buffered binary or text file object just to
create an empty file.

Replace also os.fdopen(handle).close() by os.close(handle).

1 files changed, 6 insertions, 1 deletions

diff --git a/Lib/test/support.py b/Lib/test/support.py
index d4010f4..2ce013f 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -40,7 +40,7 @@ __all__ = [
     "is_resource_enabled", "requires", "requires_linux_version",
     "requires_mac_ver", "find_unused_port", "bind_port",
     "IPV6_ENABLED", "is_jython", "TESTFN", "HOST", "SAVEDCWD", "temp_cwd",
-    "findfile", "sortdict", "check_syntax_error", "open_urlresource",
+    "findfile", "create_empty_file", "sortdict", "check_syntax_error", "open_urlresource",
     "check_warnings", "CleanImport", "EnvironmentVarGuard", "TransientResource",
     "captured_stdout", "captured_stdin", "captured_stderr", "time_out",
     "socket_peer_reset", "ioerror_peer_reset", "run_with_locale", 'temp_umask',
@@ -596,6 +596,11 @@ def findfile(file, here=__file__, subdir=None):
         if os.path.exists(fn): return fn
     return file
 
+def create_empty_file(filename):
+    """Create an empty file. If the file already exists, truncate it."""
+    fd = os.open(filename, os.O_WRONLY | os.O_CREAT | os.O_TRUNC)
+    os.close(fd)
+
 def sortdict(dict):
     "Like repr(dict), but in sorted order."
     items = sorted(dict.items())